Manawatu Round 3: Can we interpret the evidence reliably?

As always, it is a pleasure to hear from the Admin of the Manawatu Christian Apologetics Society. In response to my last post and comment, Admin replies:

Professor, Apologetics breaks into at least two streams: evidentialism and presuppositionalism. No evidence is interpreted in a vacuum; it always comes thru a filter of some type.

Apparently this was intended to address my question about the goal of his apologetic if he truly feels that evidence is “somewhat of an excuse.” What he overlooks here is that there is more you can do with the evidence after it “comes through a filter of some type.”

The most fundamental principle of science is that truth is consistent with itself (i.e. does not contradict itself). People who aren’t used to scientific thinking may not realize the tremendous power that resides in this principle. For one thing, the self-consistency of truth makes it possible to tell whether or not our conclusions have “filtered” the evidence to the point that they no longer reflect the truth accurately.

The realm of objective reality is truth, and does not contradict itself. It’s also the source of the evidence we work with in science and apologetics. Thus, the evidence, at its source, is consistent with itself and with the real world. As we study the evidence, and try to understand the evidence, it may be the case that we arrive at a distorted interpretation that no longer reflects real-world truth. But is that the end of the story? Are we helpless, and unable to escape the perceptual prison of our own biases?

No, because truth is consistent with itself. Once we look at the evidence and draw our conclusions, we can go back to the real world and see if our conclusions are consistent with themselves and with objective reality. We can, in other words, give our conclusions a reality check. If we have inadvertently distorted the truth in seeking to interpret the evidence, the result will be something that is inconsistent somewhere, either with itself (internal inconsistency) or with reality (external inconsistency). Thus, while we cannot always know that a given answer is right (since we might find some new evidence, with a new inconsistency, tomorrow), we can know when our conclusions are not consistent with the truth.

What if we find that something is internally or externally inconsistent? This is where the science comes in. We consider different alternatives, different hypotheses. If we suppose that X is true, but X turns out to be inconsistent with something that we can observe and verify in the real world, then it’s time to look at Y and Z, to see if they would produce results that are more consistent with what we see in the real world. What’s more, we can look at exactly how X is inconsistent with reality, and the nature of the inconsistency itself can often give us some hints as to which direction we should look for the true answer.

Note that it is important to work forwards and not backwards in evaluating our conclusions. That is, if we decide that X looks like it’s true, we need to consider what specific, predictable consequences ought to arise if X actually exists/occurs in the real world, and then check to see whether or not these consequences are there. For example, if Santa lands a reindeer-drawn sleigh on a snowy rooftop, slides down the chimney, and leaves presents under the tree, then this series of events ought to produce some predictable consequences. For example, we should find sleigh tracks in the snow on the roof, and reindeer tracks (and possibly dung) as well. There ought to be places in the chimney where the soot has been brushed up against. Here and there, we ought to find hairs that have dropped off the fur lining around Santa’s cuffs and hood. And so on.

Forward thinking takes the Santa conjecture, and looks at what the consequences would be if Santa really did fly in and drop down the chimney, and then checks to see whether or not the real world evidence is consistent with these expected consequences. Backwards thinking is when we have a purported cause (Santa), and a set of real-world evidence (undisturbed roofs and chimneys) and simply invent whatever scenario we can think of that would reconcile the purported cause with the actual evidence. This is mere rationalization, and we can do it no matter what the evidence is or what cause we are attempting to defend. In other words, it’s essentially useless, since it has no relationship to the question of whether or not our conclusion is actually true.

Backwards thinking is ok if we are looking for ideas as to what the truth might be. It’s a form of speculation, and speculation is a good way to come up with ideas that we can test to see whether or not they’re true. Once we’ve enumerated our ideas, however, it’s time to turn from speculation to verification, and to do that, we use forwards thinking. We look at the evidence, draw our (possibly biased) conclusions, and then go back and review the evidence to see whether or not our conclusions fit the facts. This is how science works, and it performs so well that today there are entire books and ministries and web sites dedicated to convincing people that Christianity is scientific. No matter what some may say about the authority of Scripture, the authority of science is what people–including Christians–actually respect.

So the problem is not that there is no possible way to escape our subjective biases. The problem is that some people want to look at the evidence, draw a (possibly biased) conclusion, and then stop. But that’s not how you get to the real truth. If you want to learn the real-world truth, you need to keep going even after you’ve drawn your conclusions. It’s more work, and sometimes leads to answers that do not please our personal biases, but it’s worth it. Truth does not contradict itself, and therefore we can successfully reconstruct the truth even when our conclusions have been distorted by our subjective biases.